Dresden 2011 – wissenschaftliches Programm
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TT: Fachverband Tiefe Temperaturen
TT 48: CE: Metal-Insulator Transition 2
TT 48.8: Vortrag
Donnerstag, 17. März 2011, 12:30–12:45, HSZ 105
Giant Chemical Shifts of the Sulphur 2s-Line Close to the Glass-Like Transition of CT Salt κ-(BEDT-TTF)2Cu[N(CN)2]Br- a Hard X-ray Photoemission Study — •G. Schönhense1, M. de Souza2, K. Medjanik1, A. Gloskovskii3, H.J. Elmers1, J. Müller2, and M. Lang2 — 1Institut für Physik, J. Gutenberg Univ. Mainz — 2Institut für Physik, J. Wolfgang von Goethe Universität Frankfurt — 3Institut für Anorganische und Analytische Chemie, J. Gutenberg Univ. Mainz
The organic (super-)conductors of the κ-(ET)2-X family are characterized by a strongly-correlated π - electron system with close proximity of superconductivity and antiferromagnetic insulating states and a half-filled quasi-2D metallic conduction band. HAXPES was performed at beamline P09 of PETRA III [1]. In the regions of T*∼ 45 K (anomalous metallic state) and Tg∼77K (thermal glass-like transition), the S 2s core level spectrum changes dramatically in warming-up series: around T*, the main-line intensity drops to 80 % of its initial value and a high-binding-energy shoulder arises. When approaching Tg, it further drops to 40 % and several new peaks appear, being strongly shifted by up to more than 10eV. Above the glass-transition, all satellites disappear instantaneously and the main line intensity jumps back to its initial value. This gives further evidence for changes in the electronic degrees of freedom at the T* transition and indicates that the latter may be involved in the glass-like transition, as was already speculated in literature.
Funded by DFG/TR49, Graduate School of Excellence MAINZ, and COMATT.
A.Gloskovskii et al., this conference;